Elements which have high electronegativities occur in Group: IA IIA VIIA O

Calculate the expected ph values of the buffer systems from the experiments (a,b,c,d), using the henderson- hasselbalch equation, ph-pka+log[a-]/[ha]. use for pka values carbonic acid= 6.37, and acetic acid= 4.75.

Marcel just purchased 1.69 grams of iron fillings in order to make living putty for his 6 year old niece. how many moles of iron are made in his sample?

Find the mass, in grams, of 5.00*10^23 molecules of f2